Hikiamides A–C, Cyclic Pentadepsipeptides from <i>Fusarium</i> sp. TAMA 456

Three new cyclic pentadepsipeptides, hikiamides A–C (<b>1</b>–<b>3</b>), were isolated from the culture extract of <i>Fusarium</i> sp. TAMA 456. The structures were determined by spectroscopic analysis using NMR and MS, and the absolute configurations were established by using Marfey’s method and chiral HPLC analysis. Hikiamides induced the differentiation of murine ST-13 preadipocytes into mature adipocytes at 2 μM and adiponectin mRNA expression (5- to 13-fold higher than control). They also induced PPAR-γ-dependent gene expression at a concentration from 0.63 to 10 μM in a gene reporter assay

Nonthmicin, a Polyether Polyketide Bearing a Halogen-Modified Tetronate with Neuroprotective and Antiinvasive Activity from <i>Actinomadura</i> sp.

Nonthmicin (<b>1</b>), a new polyether polyketide bearing a chlorinated tetronic acid, was isolated from the culture extract of a soil-derived <i>Actinomadura</i> strain. The structure of <b>1</b> was elucidated by interpretation of NMR and MS spectroscopic data, and the absolute configuration of <b>1</b> was proposed on the basis of the crystal structure of its dechloro congener ecteinamycin (<b>2</b>) also isolated from the same strain. Tetronic acids modified by halogenation have never been reported from natural products. Compounds <b>1</b> and <b>2</b> were found to have neuroprotective activity and antimetastatic properties at submicromolar concentrations in addition to antibacterial activity